Saturday, December 17, 2011

NYTimes: As Permafrost Thaws, Scientists Study the Risks

The Times hit it out of the park with this one. They covered the major points of the science, sketched how our understanding has changed, and provided real numbers for the estimated impact:

For now, scientists have many more questions than answers. Preliminary
computer analyses, made only recently, suggest that the Arctic and
sub-Arctic regions could eventually become an annual source of carbon
equal to 15 percent or so of today’s yearly emissions from human
activities.

But those calculations were deliberately cautious. A recent survey
drew on the expertise of 41 permafrost scientists to offer more
informal projections. They estimated that if human fossil-fuel burning
remained high and the planet warmed sharply, the gases from permafrost
could eventually equal 35 percent of today’s annual human emissions.

The experts also said that if humanity began getting its own emissions
under control soon, the greenhouse gases emerging from permafrost could
be kept to a much lower level, perhaps equivalent to 10 percent of
today’s human emissions.

It sounds like a little thing, but I can't tell you how main mainstream news stories:

1) Avoid using numbers completely.
2) Take the first number they are told and put it in the article, not caring whether the number means anything (here they convert it to a % of human emissions, perfect).
3) Stick to one central number, assuming people will be hopelessly confused by the reality of different estimates.

The author gets to the point of what the numbers mean, too:

Even at the low end, these numbers mean that the long-running
international negotiations over greenhouse gases are likely to become
more difficult, with less room for countries to continue burning large
amounts of fossil fuels.

The whole article does a great job. Good numbers with appropriate caveats:

Scientists need better inventories of the ancient carbon. The best estimate
so far was published in 2009 by a Canadian scientist, Charles Tarnocai,
and some colleagues. They calculated that there was about 1.7 trillion
tons of carbon in soils of the northern regions, about 88 percent of it
locked in permafrost. That is about two and a half times the amount of
carbon in the atmosphere.

Followed by context:

Philippe Ciais, a leading French scientist, wrote at the time that he
was “stunned” by the estimate, a large upward revision from previous
calculations.
“If, in a warmer world, bacteria decompose organic soil matter faster,
releasing carbon dioxide,” Dr. Ciais wrote, “this will set up a positive
feedback loop, speeding up global warming.”

It may be small of me, but I like a little action in my science stories. It reminds us of the absurdity of the denialist portrait of the rent-seeking elitist ivory-tower scientist, running computer simulations from a desk and collecting grant money:

One recent day, in 11-degree weather, Dr. Walter Anthony and an
assistant, Amy Strohm, dragged equipment onto two frozen thermokarst
lakes near Fairbanks. The fall had been unusually warm and the ice was
thin, emitting thunderous cracks — but it held. In spots, methane
bubbled so vigorously it had prevented the water from freezing. Dr.
Walter Anthony, six months pregnant, bent over one plume to retrieve
samples.

Well, they know now. And it's for the good of the public; they need to know what scientists really do.

They don't shy away from explaining how unusual these emissions are:

Dr. Walter Anthony had already run chemical tests on the methane from
one of the lakes, dating the carbon molecules within the gas to 30,000
years ago. She has found carbon that old emerging at numerous spots
around Fairbanks, and carbon as old as 43,000 years emerging from lakes
in Siberia.

“These grasses were food for mammoths during the end of the last ice
age,” Dr. Walter Anthony said. “It was in the freezer for 30,000 to
40,000 years, and now the freezer door is open.”

And they talk about the danger of fire:

One day in 2007, on the plain in northern Alaska, a lightning strike set the tundra on fire.
Historically, tundra, a landscape of lichens, mosses and delicate
plants, was too damp to burn. But the climate in the area is warming and
drying, and fires in both the tundra and forest regions of Alaska are
increasing.

Are they going to leave it there? No, they are going to give you context for the effect of this fire:

Scientists have calculated that the fire and its aftermath sent a huge
pulse of carbon into the air — as much as would be emitted in two years
by a city the size of Miami.

As well as what the fire means in the broader context of the permafrost:

Scientists say the fire thawed the upper
layer of permafrost and set off what they fear will be permanent shifts
in the landscape.

Up to now, the Arctic has been absorbing carbon, on balance, and was
once expected to keep doing so throughout this century. But recent
analyses suggest that the permafrost thaw could turn the Arctic into a
net source of carbon, possibly within a decade or two, and those studies
did not account for fire.

“I maintain that the fastest way you’re going to lose permafrost and
release permafrost carbon to the atmosphere is increasing fire
frequency,” said Michelle C. Mack, a University of Florida scientist who
is studying the Anaktuvuk fire. “It’s a rapid and catastrophic way you could completely change everything.”

Almost everyone agrees that the legacy media in general and science journalism in particular are on the rocks these days, but Justin Gillis seems not to have gotten the memo. This article is going to win some awards.